src/common/sessiond-comm/inet.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <limits.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <errno.h>
  28
  29 #include <common/defaults.h>
  30 #include <common/error.h>
  31
  32 #include "inet.h"
  33
  34 /*
  35  * INET protocol operations.
  36  */
  37 static const struct lttcomm_proto_ops inet_ops = {
  38         .bind = lttcomm_bind_inet_sock,
  39         .close = lttcomm_close_inet_sock,
  40         .connect = lttcomm_connect_inet_sock,
  41         .accept = lttcomm_accept_inet_sock,
  42         .listen = lttcomm_listen_inet_sock,
  43         .recvmsg = lttcomm_recvmsg_inet_sock,
  44         .sendmsg = lttcomm_sendmsg_inet_sock,
  45 };
  46
  47 /*
  48  * Creates an PF_INET socket.
  49  */
  50 __attribute__((visibility("hidden")))
  51 int lttcomm_create_inet_sock(struct lttcomm_sock *sock, int type, int proto)
  52 {
  53         int val = 1, ret;
  54
  55         /* Create server socket */
  56         if ((sock->fd = socket(PF_INET, type, proto)) < 0) {
  57                 PERROR("socket inet");
  58                 goto error;
  59         }
  60
  61         sock->ops = &inet_ops;
  62
  63         /*
  64          * Set socket option to reuse the address.
  65          */
  66         ret = setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(int));
  67         if (ret < 0) {
  68                 PERROR("setsockopt inet");
  69                 goto error;
  70         }
  71
  72         return 0;
  73
  74 error:
  75         return -1;
  76 }
  77
  78 /*
  79  * Bind socket and return.
  80  */
  81 __attribute__((visibility("hidden")))
  82 int lttcomm_bind_inet_sock(struct lttcomm_sock *sock)
  83 {
  84         int ret;
  85
  86         ret = bind(sock->fd, &sock->sockaddr.addr.sin,
  87                         sizeof(sock->sockaddr.addr.sin));
  88         if (ret < 0) {
  89                 PERROR("bind inet");
  90         }
  91
  92         return ret;
  93 }
  94
  95 /*
  96  * Connect PF_INET socket.
  97  */
  98 __attribute__((visibility("hidden")))
  99 int lttcomm_connect_inet_sock(struct lttcomm_sock *sock)
 100 {
 101         int ret, closeret;
 102
 103         ret = connect(sock->fd, (struct sockaddr *) &sock->sockaddr.addr.sin,
 104                         sizeof(sock->sockaddr.addr.sin));
 105         if (ret < 0) {
 106                 /*
 107                  * Don't print message on connect error, because connect is used in
 108                  * normal execution to detect if sessiond is alive.
 109                  */
 110                 goto error_connect;
 111         }
 112
 113         return ret;
 114
 115 error_connect:
 116         closeret = close(sock->fd);
 117         if (closeret) {
 118                 PERROR("close inet");
 119         }
 120
 121         return ret;
 122 }
 123
 124 /*
 125  * Do an accept(2) on the sock and return the new lttcomm socket. The socket
 126  * MUST be bind(2) before.
 127  */
 128 __attribute__((visibility("hidden")))
 129 struct lttcomm_sock *lttcomm_accept_inet_sock(struct lttcomm_sock *sock)
 130 {
 131         int new_fd;
 132         socklen_t len = 0;
 133         struct lttcomm_sock *new_sock;
 134
 135         if (sock->proto == LTTCOMM_SOCK_UDP) {
 136                 /*
 137                  * accept(2) does not exist for UDP so simply return the passed socket.
 138                  */
 139                 new_sock = sock;
 140                 goto end;
 141         }
 142
 143         new_sock = lttcomm_alloc_sock(sock->proto);
 144         if (new_sock == NULL) {
 145                 goto error;
 146         }
 147
 148         /* Blocking call */
 149         new_fd = accept(sock->fd, (struct sockaddr *) &new_sock->sockaddr.addr.sin,
 150                         &len);
 151         if (new_fd < 0) {
 152                 PERROR("accept inet");
 153                 goto error;
 154         }
 155
 156         new_sock->fd = new_fd;
 157         new_sock->ops = &inet_ops;
 158
 159 end:
 160         return new_sock;
 161
 162 error:
 163         free(new_sock);
 164         return NULL;
 165 }
 166
 167 /*
 168  * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
 169  */
 170 __attribute__((visibility("hidden")))
 171 int lttcomm_listen_inet_sock(struct lttcomm_sock *sock, int backlog)
 172 {
 173         int ret;
 174
 175         if (sock->proto == LTTCOMM_SOCK_UDP) {
 176                 /* listen(2) does not exist for UDP so simply return success. */
 177                 ret = 0;
 178                 goto end;
 179         }
 180
 181         /* Default listen backlog */
 182         if (backlog <= 0) {
 183                 backlog = LTTNG_SESSIOND_COMM_MAX_LISTEN;
 184         }
 185
 186         ret = listen(sock->fd, backlog);
 187         if (ret < 0) {
 188                 PERROR("listen inet");
 189         }
 190
 191 end:
 192         return ret;
 193 }
 194
 195 /*
 196  * Receive data of size len in put that data into the buf param. Using recvmsg
 197  * API.
 198  *
 199  * Return the size of received data.
 200  */
 201 __attribute__((visibility("hidden")))
 202 ssize_t lttcomm_recvmsg_inet_sock(struct lttcomm_sock *sock, void *buf,
 203                 size_t len, int flags)
 204 {
 205         struct msghdr msg;
 206         struct iovec iov[1];
 207         ssize_t ret = -1;
 208
 209         memset(&msg, 0, sizeof(msg));
 210
 211         iov[0].iov_base = buf;
 212         iov[0].iov_len = len;
 213         msg.msg_iov = iov;
 214         msg.msg_iovlen = 1;
 215
 216         msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin;
 217         msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
 218
 219         if (flags == 0) {
 220                 flags = MSG_WAITALL;
 221         }
 222
 223         do {
 224                 ret = recvmsg(sock->fd, &msg, flags);
 225         } while (ret < 0 && errno == EINTR);
 226         if (ret < 0) {
 227                 PERROR("recvmsg inet");
 228         }
 229
 230         return ret;
 231 }
 232
 233 /*
 234  * Send buf data of size len. Using sendmsg API.
 235  *
 236  * Return the size of sent data.
 237  */
 238 __attribute__((visibility("hidden")))
 239 ssize_t lttcomm_sendmsg_inet_sock(struct lttcomm_sock *sock, void *buf,
 240                 size_t len, int flags)
 241 {
 242         struct msghdr msg;
 243         struct iovec iov[1];
 244         ssize_t ret = -1;
 245
 246         memset(&msg, 0, sizeof(msg));
 247
 248         iov[0].iov_base = buf;
 249         iov[0].iov_len = len;
 250         msg.msg_iov = iov;
 251         msg.msg_iovlen = 1;
 252
 253         switch (sock->proto) {
 254         case LTTCOMM_SOCK_UDP:
 255                 msg.msg_name = (struct sockaddr *) &sock->sockaddr.addr.sin;
 256                 msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
 257                 break;
 258         default:
 259                 break;
 260         }
 261
 262         do {
 263                 ret = sendmsg(sock->fd, &msg, flags);
 264         } while (ret < 0 && errno == EINTR);
 265         if (ret < 0) {
 266                 /*
 267                  * Only warn about EPIPE when quiet mode is deactivated.
 268                  * We consider EPIPE as expected.
 269                  */
 270                 if (errno != EPIPE || !lttng_opt_quiet) {
 271                         PERROR("sendmsg inet");
 272                 }
 273         }
 274
 275         return ret;
 276 }
 277
 278 /*
 279  * Shutdown cleanly and close.
 280  */
 281 __attribute__((visibility("hidden")))
 282 int lttcomm_close_inet_sock(struct lttcomm_sock *sock)
 283 {
 284         int ret;
 285
 286         /* Don't try to close an invalid marked socket */
 287         if (sock->fd == -1) {
 288                 return 0;
 289         }
 290
 291         ret = close(sock->fd);
 292         if (ret) {
 293                 PERROR("close inet");
 294         }
 295
 296         /* Mark socket */
 297         sock->fd = -1;
 298
 299         return ret;
 300 }